Antifriction bearing assembly for earth boring drills



April 6, 1937. c. E. REED ANTIFRICTION BEARING ASSEMBLY FOR EARTH BORING DRILLS Filed Nov. 6, 1935 mvnl'raR; Clai ence E.Reed,

M1 IORNEY Patented Apr. 6, 1937 ANTIFRICTION BEARING ASSEMBLY FOR- EARTH BORING DRILLS Clarence E. Reed, Wichita, Kans., assignor to Chicago Pneumatic Tool Company, New York, N. Y., a corporation of New Jersey Application November 6,1935, Serial No. 48,576 4 Claims. (01. 255-71) lies in the features and comthis shoulder I4 is of sumcient width to afiord angement of parts hereinafter a bearing surface for the entire end face of the particularly pointed out in the conical rollers at their smaller ends, which point in a direction towards the vertical axis of'the drill indicated by the dotted line 11-11, it being understood that the organization is of that general type in which a spindle projects downwardly and inwardly from its support towards the vertical axis of the drill, said support including the The invention bination and arr described and claims.

The drawing shows in:

Fig. 1 a toothed roller cutter in section mounted upon a spindle with anti-friction bearings and locking means between them, the latter parts being shown in elevation.

end of the Sp ndle, bear upon the shoulder l4 wall of the cutter bore at the apex portion thereof.

of flange I 2, which face or shoulder is inclined Next, the cylindrical roller bearings are introto the axis of the spindle t conform to and furduced through the annular space be een the nish a bearing for the small end faces of the flange at the base of the cutter and vthe 55 frusto-conical cylindrical peripheral surface of thestem l of rollers, and it will be noted that Fig. 2 is a View of a removable section of the shank above mentioned, which extends up into spindle. a seat in the bit head to which it is fastened. In the drawing there is indicated a spindle The larger outer ends of the tapered roller bearsupport formed in one piece with a body portion ings engage the flange 8, said flange being underl, a shank portion 2, which latter is adapted to cut at 8a, to receive a part of th l r end of be secured in the bit head, and a spindle poreach tapered roller, the flange reaching to about tion 3 which has an annular flange 3a and a the axial center of the end face of said roller. shoulder 31). Within this annular portion of the The head or flange I! at the extreme inner or main spindle section 3 is fitted the stem 4 of a ree end of e sp n e s a terminal face or removable section 5 of the spindl s id t m friction bearing l2a of frusto-conical form. The having a reduced end 6 extending through the incline of this face is substantially coincident body of the support into a. reces 1 th r f, wh r with the inclin'e of the face of the tapered'r'ollers. it is secured by welding. This terminal or free The roller cutter II is formed in one piece with end section of the spindle has a fla a formed a toothed frusto-conical zone l5a and a toothed in one piece therewith; which fits against the e z b which may be, as s w oend face of the annular flange 3a of the f i conical, but higher in projected altitude than the section of the spindle and extends outwardly altitude f the pex Z0116 beyond the periphery of sald flange and forms Th s cutter encloses the free end of the spindle between itself and the shoulder 3b a groove or and it has a frusto-conical bore, the W raceway 9 adapted t receive cylindrical roller of which bears frictionally on the tapered face 0 bearings l0 which take radial loads, and as hereat the extreme end of the spindle and on inafter pointed t th roller bearings play a the conical roller bearings I 3. This tapered bore part in looking the roller cutter ll rotatively on continues Substantially to the Point from the spindle. The extreme free end of the terwhich point the Wall the is cylindricalminal section of the spindle has a head or flange the flange projecting inwardly at h base l2 of reduced diameter as compared with the of e cuttergand contacts withem maximum diameter of the spindle, and between of the cylindrical roller bearings i this head or flange and the flange 8 of said ter- The flange at the base of the roller cutter engages the end face of the cylindrical roller mmal section there is a frusto-conical zone 5a bearings m and the face of this flange at the 40 which tapers i the free endpfthe f base thereof bears frictionally at l5f upon the base of this i zone i or peripheral surface of the main part of the spindle less diameter than the adjoining flange 8 and at the base thereof the small end of this tapered zone is of less organization'can be assembled by placing; diameter than the head or flange l2 at the inner the conical rollers 1n the raceway or groove free end of the Spindleformed by the, tapered portion of the terminal in the groove or raceway thus provl section of the spindle, then placing this end sectween the flanges and conical roller h tionof the spindle with the tapered rollers thereings l3 are located to roll on the conicalsurface on th th apex ti of th bore of t of the spindle. The small ends of these tapered tt t t tre tapered face of t rollers, i. e., the ends thereof nearest the free spindle in frictional contact with the tapered cylindrical wall of the bore at the base zone of the cutter. Then the main section of the spindle is inserted with its flange occupying the space between the cylindrical roller bearings and the cylindrical stem 4 of the terminal section of the spindle with the shoulder 3b engaging the end face of the roller bearing and with the cylindrical surface of the main part of the spindle in frictional contact with the wall of the bore of the base flange of the cutter i. eat I5 Then the reduced end of the terminal section is welded to and the assembly is complete.

It will be noticed that the conical roller cutter has an annular friction its base bore and an annular tapered friction surface at the inner end portion of the apex portion of its bore.

The flange or head at the extreme inner end of the spindle covers the face at the smaller end of the conical roller, of the full diameter thereof and said head furnishes an annular tapered friction bearing face at its extreme end with which the wall ofthe tapered bore at the apex portion of the cutter contacts. The organization therefore presents limited friction bearing surfaces between the cutter and spindle at each end of the spindle, with cylindrical roller bearings sustaining radial loads and tapered roller bearings sustaining end thrust of the cutter outwardly towards the spindle support, or in other words, thruststhat take place in a direction radially outward from the vertical axis yy of the drill organization.

. These tapered rollers also sustain thrusts which are substantially upward relative to the bottom of the hole being drilled.

The cylindrical roller bearings lock thewroller cutter rotatively on the spindle by reason of the the cutter support base flange of the cutter contacting the outer side faces of these rollers.

The frictional bearing at the bore of the base flange of the cutter contributes a steadying effeet to the action of the cutter which is aided also by the friction bearing between the. apex portion of the cutter bore and the extreme end of the spindle, which effect is of advantage at all times and particularly after some wear has taken place.

Because the tapered wall of the cutter bore extends clear to its point of junction with the cylindrical raceway portion in the base of the cutter, the cylindrical roller bearings are relieved of all end thrust outwardly toward the spindle support. Also because the head or flange at the free end of .the spindle covers the full diameter of end faces of conical rollers there will be no end thrust of the cutter imposed on said rollers at this point, these rollers, however, as above thrust of the cutter outwardly mentioned taking by reason of the wall of the tapered bore of the cutter contacting the peripheral surface of the rollers. p A

This present application concerns certain modifications of the structure disclosed in applicants copend-ing application Serial No. 28,329, filed June 25, 1935. j

stem of the spindles bearing surface within A friction bearing between the free end of the spindle and the wall of the cutter bore at the apex portion of said bore, and rolling bearings between the cutter and the spindle, including cylindrical rollers and tapered rollers located at a zone of said spindle intermediate the annular tapered friction bearing and the said friction bearing at the bases of the cutter and spindle, the wall of the cutter bore being tapered to bear on said tapered rollers and coincident with the tapered friction bearing portion of said wall.

2. A roller cutter and spindle organization for earth boring drills comprising a roller cutter having a tapered bore, a spindle having a flange at itsinner end, and a tapered surface comple- I mentary to the tapered wall of the cutter bore, tapered rollers between said tapered surface of the spindle and the complementary wall of the cutter, said flange covering the full diameter of the end faces at the small ends of the tapered rollers, said flange having also an annular friction bearing for the cutter, said tapered rollers taking radial thrust and end thrust of the cutter only through contact of the cutter with the peripheries of the frustoconical rollers, and cylindrical rollers between the base portions of said roller cutter and spindle, substantially as described.

3. In a roller cutter and spindle assembly for earth boring drills, the combination of a spindle, a toothed rotary cutter of frustoconical form, complementary friction bearing surfaces of limited area at each end of-the spindle and the wall of the cutter bore, cylindrical roller bearings between the spindle and the roller cutter sustaining radial loads, and tapered roller bearings between the spindle and the roller cutter, nearer the free end of the spindle than the cylindrical roller bearings and sustaining end thrust of the cutter outwardly from the vertical axis of the drill towards the spindle support, said spindle having an annular flange at its free end covering the full diameter of the end faces at the smaller ends of the tapered roller bearings, substantially front of said flange, thebore of the cutter being tapered in front of said cylindrical raceway and extending uniformly all the way to the apex portion of said cutter, a spindle having a cylindrical raceway surface, roller bearings between the same and the cylindrical raceway of the cutter, said spindle having a tapered raceway and a terminal flange with a tapered end face complementary to and borne upon by a portion of the uniformly tapered wall of the cutter bore, and tapered rollers between the tapered raceway of the spindle and the wall of the tapered bore of the cutter,

.said terminal flange providing the inner wall of said tapered raceway.

CLARENCE E. REED. 

